<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<link rel="stylesheet" href="css/buttons-min.css">
<meta name="viewport" content="width=device-width, initial-scale=1">

 <body> 
  <form name="form1 "> 
   <select id="yyyy" name="YYYY " onchange="YYYYMM(this.value)"> <option value="">请选择 年</option> </select> 
   <select id="mm" name="MM " onchange="MMDD(this.value)"> <option value="">选择 月</option> </select> 
   <select id="dd" name="DD "> <option value="">选择 日</option> </select> 
  </form> 
<script>


</script>
	</body>
</html > 